Optical coherence tomography (OCT) using multi-wavelength light-wave interference can obtain tomographic images of specimens (particularly the fundus) at high resolution.
In recent years, the field of ophthalmologic OCT has seen advance in development of polarization sensitive OCT where polarization parameters (retardation and orientation) which are a type of optical properties of fundus tissue are used to perform imaging, in addition to normal OCT where the shape of the fundus tissue is imaged.
A polarization sensitive OCT image can be configured and fundus tissue can be distinguished and segmented (processing where boundaries of layers are calculated from tomographic image data) using polarization parameters in polarization sensitive OCT. Accordingly, tissue which has been difficult to diagnose using luminance information can be distinguished, thereby providing pathological support for diagnosis of glaucoma and so forth.
In polarization sensitive OCT, light, which has been modulated into circularly-polarized light is used as measurement light to observe a specimen, and interference light is split as two orthogonal linearly-polarized lights and detected, thereby generating a polarization sensitive OCT image (see PTL 1).